The objective of this study was to investigate the effect of earthworms and arbuscular mycorrhiza (AM) on the Cd transfer from soil to plant The Aquods soil, obtained from Laitiao Village, Hong Kong, was amended with Cd which Concentration is 5, 10 and 20 mg•kg-1 respectively. After two months amendment, the soil was inoculated with eight earthworms (Pheretina sp.) and arbuscular mycorrhiza (Inoculum Endorize-Mix2) separately, and in combiantions Both blank and inoculated samplepotswere received 15 pre germinated ryegrass seeds (Lolium multiflonwn).The results showed that(1) the soil pH decreased by about 0.2 units with earthworms inoculation, while no soil pH change was observed with mycorrhiza inoculation The combination of earthworms and mycorrhiza inoculation was not able to reduce the soil pH to the same level as earthworms alone (2) the concentration of dissolved organic carbon (DOC) in soil was significantly increased with earthworms and mycorrhiza inoculation, with the effect of earthworm outweighed that of mycorrhiza The combination of earthworms and mycorrhiza inoculation did not significantly increase the DOC compared with earthworms alone (3) mycorrhiza inoculation significantly increased Cd concentration in shoot and root, however earthworm alone only significantly increased Cd concentration in root Earthworms mycorrhiza combination increased the Cd transfer from ryegrass root to shoot (4) The concentration of DTPA extractable Cd in earthworm castor in soil was positively correlatedwith iyegrass uptake of Cd (p <0.01) , and the concentration of DTPA-extractable Cd in earthworm castwas higher than that in soil (p <0.05).Therefore, the available Cd in earthworm cast was the important source of Cd uptake by plant